Fig. 13.

Eddy momentum transport for Saturn from Cassini ISS. The eastward and northward eddy winds u′ and v′ are the departures from the zonal means. Their product $\overline{u^{\prime }{v}^{\prime }}$ averaged over longitude and multiplied by density is the northward eddy flux of eastward momentum. The fact that this quantity has the same sign as $\partial \overline{u}/\partial y$, which is the increase of the mean eastward wind with latitude, says that the eddies are putting energy into the jets and not the reverse. The left panel is $\overline{u}$, the middle panel is $\overline{u^{\prime }{v}^{\prime }}$, and the right panel is the number of velocity measurements per 0.5° latitude bin (Del Genio and Barbara 2012)